This implementation science research project aims to evaluate innovative strategies to expand pediatric HIV diagnosis and linkage to care. Over 90% of the 3.2 million HIV-infected children in the world live in sub- Saharan Africa, many of whom are undiagnosed. In the absence of treatment, pediatric HIV has a far more aggressive course than adult infection and the benefits of antiretroviral treatment are limited when treatment is deferred until children are symptomatic. Children born before the scale up of PMTCT programs, and children who slip through the cracks in the PMTCT cascade remain untested and at risk for severe illness and death. Targeted HIV testing for the children of HIV-infected adults in care is an efficient case detection strategy that identifies a high prevalence of pediatric HIV; however, pediatric HIV testing rates remain low. A health systems-level approach to optimizing the delivery and tracking of pediatric HIV testing services in the pediatric HIV testing and care cascade may complement and improve current pediatric HIV diagnosis approaches. This study will 1) identify health facility level factors associated with high and low pediatric HIV testing rates, and 2) adapt and test the Systems Analysis and Improvement Approach (SAIA) previously used to enhance PMTCT (R01, Principal investigator: Sherr) to determine whether it can improve pediatric HIV testing rates and linkage to care. In Aim 1, we will use routinely collected pediatric HIV testing indicator data and remote surveys through a partnership with the National AIDS and STI Control Programme (NASCOP); we will compare high and low pediatric HIV- testing facilities to identify potentially modifiable facility-level characteristics, which ca be evaluated during the adapted SAIA intervention. In Aim 2, we will conduct a cluster randomized controlled trial (cRCT) in Kenya using the 12 sites from the SAIA trial. The SAIA approach involves classical industrial engineering methods- cascade analysis, process mapping, and continuous quality improvement-and has been successful in optimizing PMTCT delivery services. We will collect routine, monthly pediatric HIV testing and linkage to care indicator data for each facility and compare the change in a) testing rates and b) linkage to care between intervention and control facilities during pre-intervention, intervention, and post-intervention periods. If found to be effective and sustainable, this low-cost and flexible intervention may provide a new tool for optimizing pediatric HIV testing and linkage to care.